/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityManager.h
Iterate all children, grandchildren etc of the specified entity using a parent first traversal
template<typename IteratorType> void IterateChildren_ParentFirst ( [FMovieSceneEntityID](API\Runtime\MovieScene\EntitySystem\FMovieSceneEntityID) ParentID, IteratorType && Iterator ) const